Cyclosporine helps prevent rejection of a transplanted organ by suppressing the immune system.

Grapefruit juice slows the body's normal breakdown of several drugs, including cyclosporine, allowing it to build up to potentially excessive levels in the blood.
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A recent study indicates this effect can last for three days or more following the last glass of juice.
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If you take cyclosporine, the safest approach is to avoid grapefruit juice altogether.

The herb St. John's wort
(Hypericum perforatum)
is primarily used to treat mild to moderate depression.

St. John's wort has the potential to accelerate the body's normal breakdown of certain drugs
3,4
including cyclosporine, resulting in lower blood levels of these drugs.

This interaction appears to have occurred in two heart transplant patients taking cyclosporine, leading to heart transplant rejection.
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These individuals had been doing well after transplantation while taking standard immunosuppressive therapy that included cyclosporine. After starting St. John's wort for depression, however, they began experiencing problems and their blood levels of cyclosporine were found to have dipped below the therapeutic range. After St. John's wort was discontinued, cyclosporine levels returned to normal and no further episodes of rejection occurred.

Numerous cases of transplant rejection episodes involving the heart, kidney, and liver have also been reported in people using the herb.
6,7

Based on this evidence, if you are taking cyclosporine, you should not take St. John's wort.

The supplement ipriflavone is used to treat osteoporosis. A 3-year, double-blind trial of almost 500 women, as well as a small study, found worrisome evidence that ipriflavone can reduce white blood cell count in some people.
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For this reason, anyone taking medications that suppress the immune system should avoid taking ipriflavone.

An animal study indicates that use of peppermint oil may increase cyclosporine levels in the body.
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If you are taking cyclosporine and wish to use peppermint oil as well, notify your physician in advance, so that your blood levels of cyclosporine can be monitored and your dose adjusted if necessary.
If you are already taking both peppermint oil and cyclosporine and stop taking the peppermint, your cyclosporine levels may fall. Again, consult your physician to make the necessary dosage adjustment.

The herb
Scutellaria baicalensis
(Chinese skullcap) may impair absorption of cyclosporine, according to a study in animals.
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Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.